1. Field of the Invention
The present invention relates generally to a dental prophylaxis angle (prophy angle), and in particular to a disposable prophy angle having a disposable prophy cup.
2. Description of the Prior Art
It is well known in the prior art to use disposable prophy angles having disposable prophy cups for performing dental procedures by a dentist or hygienist. These prophy angles are driven by a motorized dental handpiece. They are usually connected to the handpiece by inserting a nose section of the handpiece into the angle and connecting it to a drive shaft of the angle. The primary purpose of using a prophy angle is to enable the hygienist to reach more easily the various surface areas of the teeth. The main obstacles in this procedure are the hygienists hands, visibility, access and the size of the angle itself.
The prophy cups are shaped to hold a desired amount of abrasive medium (paste) which is used to clean and polish the teeth. The prior art teaches of ways to automatically feed the paste or, in other cases, to preload a definitive amount of paste. Upon performing the procedure, the prophy cup and angle are subject to contamination and infection from saliva and blood of the patient. The high cost of sterilizing these items, in terms of money and time, has made the use of reasonably priced disposable angles very practical. Another advantage in using disposable mechanisms is to eliminate the need for the dentist or hygienist having to actually handle the components during sterilization. But most importantly, is to reduce the danger from incomplete sterilization, whereby the bacteria and infection are then transferred from one patient to another.
Since every hygienist can consume thousands of disposable prophy angles each year, it is very important that they be reasonably priced. Most of the disposable prophy angles are manufactured from plastic material or inexpensive metals. Usually the plastic materials are of different grades and types depending on whether the component parts are designed to be gears, shafts or housings. Although they are used but a single time, the prior art recognizes the need for ruggedness and durability in disposable angles. It is also imperative that they not break or splinter during use.
As stated above, the primary purpose of the prophy angle is to more easily reach the various surfaces of the teeth. Unfortunately the designs of the prior art locate the main gear reduction in the head section of the prophy angle. This creates a bulkiness where it is least desired. This also demands that the housing leading to the head be larger than necessary. It also makes the weight of the prophy angle heavier at the distal end causing a balancing problem. These designs limit the length of the housing and therefore bring the hygienists hands closer to the mouth of the patient. This causes the patient to experience more discomfort, creates a visibility problem and leads to fatique of the hygienist's hands.
It is well known in the prior art that "splatter" is a problem that happens when the paste is not handled correctly by the prophy cup. There are numerous patents which address this problem. Some seek a solution in the design of the cup, while others attempt to solve the problem by providing a shield or some similar type barrier. The present invention seeks to improve upon the prior art.
Accordingly, a need will be seen for a prophy angle which will alleviate these problems and accomplish the desired end result. A discussion of the prior art, of which the present inventor is aware, and the distinctions from the present invention is provided below.
U.S. Pat. No. 5,433,605 issued to Strobl, Jr. on Jul. 18, 1995, discloses an adjustable prophy angle of which the angle can be adjusted from the standard 90.degree. to improve accessibility. The bulkiness of the angle appears to remain, if not worse, and the visibilty is not seen to be improved.
U.S. Pat. No. 5,219,285 issued to Meller et al. on Jun. 15, 1993, discloses a disposable right angle which utilizes a three piece construction with one of the pieces being made of metal to increase durability. The metal component is insertable through the housing which increases the bulkiness of the angle.
U.S. Pat. No. 5,040,978 issued to Falcon et al. on Aug. 20, 1991 shows a dental prophy angle having a single snap-on retention mechanism that is integral with the housing for retaining the prophy cup rotating member and providing smooth rotation of the cup. This is an excellent illustration of the prior art and the effort that has been made to make the angles easy to assemble. Although this feature is of importance, it does not make the access any easier nor reduce the visibility problem.
U.S. Pat. No. 4,544,356 issued to Gardella et al. on Oct. 1, 1985 teaches the use of a main shaft and a secondary shaft, but rather than utilizing a gear mechanism this patent uses a reciprocating cam to impact a reciprocating action to the cup. No attempt is made here for any gear reduction.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.